The present invention relates to a wrench for fixing a spark plug attached to an internal combustion engine.
For a conventional plug wrench using a magnet, in which a contact portion of plug is brought into contact with the short tubular magnet, the magnet is liable to be broken or cracked and there is a danger of a broken piece entering the engine because the magnet is hard and brittle. Also, if the plug is kept slightly apart from the magnet, the magnetic force for holding the plug is weak, so that the plug comes off from the plug wrench. Further, for a plug wrench of a type such that a cylindrical rubber is inserted in a wrench body and the spark plug is fixed by means of this cylindrical rubber, the rubber changes with passage of time, so that the plug wrench cannot be used for a long period of time.